Centrifugal separator with a sensor device

Abstract

A centrifugal separator has a stationary casing and a centrifuge rotor, which is provided in the stationary casing and arranged to rotate around an axis of rotation at a rotary speed and which includes a plurality of nozzles for discharge of a product from the centrifuge rotor. The centrifugal separator includes a sensor device which includes a transfer element, which has a first part and a second part and which is configured to be mounted in such a way that the first part is located inside the stationary casing and outside the centrifuge rotor and that the second part is located outside the stationary casing. At least the first part of the transfer element has an elongated shape, a receiving head, which includes the first part of the transfer element. The sensor device further includes a sensor element, which is mounted to the second part of transfer element and which is configured to sense vibrations and/or shock pulses propagating from the receiving head to the sensor element, and an evaluation unit, which communicates with the sensor element for transmitting signals from the sensor element to the evaluation unit. The transfer element is mounted in the stationary casing, directed such that the end face of the receiving head faces the passing jets from the nozzles during rotation of the rotor. A centrifugal separator with such a sensor device is also disclosed.

The invention claimed is: 
     
       1. A centrifugal separator, comprising:
 a stationary casing; 
 a centrifuge rotor, the centrifuge rotor being provided in the stationary casing and being arranged to rotate around an axis of rotation at a rotary speed, and comprising a plurality of nozzles for discharge of a product from the centrifuge rotor in a direction; 
 a sensor device, the sensor device comprising:
 a transfer element having a first part and a second part and being configured to be mounted in such a way that the first part is located inside the stationary casing and outside the centrifuge rotor and that the second part is located outside the stationary casing, at least the first part of the transfer element having an elongated shape; 
 a receiving head, the receiving head being comprised by the first part of the transfer element; 
 a sensor element, the sensor element being mounted to the second part of transfer element and being configured to sense vibrations and/or shock pulses propagating from the receiving head to the sensor element; and 
 an evaluation unit, the evaluating unit communicating with the sensor element for transmitting signals from the sensor element to the evaluation unit, 
 wherein the transfer element is mounted in the stationary casing, directed such that the end face of the receiving head faces passing jets from the nozzles during rotation of the rotor, and 
 wherein parts of an envelope surface of the transfer element, except the receiving head, are surrounded by a protecting tube which protects the first part of the transfer element from splashing and vibrations not generated from the receiving head. 
 
 
     
     
       2. The centrifugal separator according to  claim 1 , wherein the transfer element is directed such that during rotation the end face of the receiving head faces the opening of a certain nozzle at a substantially right angle. 
     
     
       3. The centrifugal separator according to  claim 1 , wherein the sensor element is attached to the end of the second part of the transfer element. 
     
     
       4. The centrifugal separator according to  claim 1 , wherein the transfer element is manufactured of a material configured to permit said propagation of vibrations from the receiving head to the sensor element. 
     
     
       5. The centrifugal separator according to  claim 1 , wherein the sensor element comprises a shock pulse transducer with an accelerometer. 
     
     
       6. The centrifugal separator according to  claim 1 , wherein the evaluation unit communicates with the sensor element via a conduit comprising a zener barrier. 
     
     
       7. The centrifugal separator according to  claim 1 , wherein the evaluation unit is configured to calculate the rotary speed of the centrifuge rotor by means of said signals. 
     
     
       8. The centrifugal separator according to  claim 1 , wherein the nozzles comprise intermittently openable nozzles and wherein the evaluation unit is configured to establish a possible leakage from the nozzles by means of said signals. 
     
     
       9. The centrifugal separator according to  claim 1 , wherein the protecting tube is suspended by a first rubber bushing between the protecting tube and the first part-of the transfer element, close to the receiving head. 
     
     
       10. The centrifugal separator according to  claim 1 , wherein the protecting tube is threaded on an exterior surface thereof to fit in a correspondingly threaded hole in the stationary casing. 
     
     
       11. The centrifugal separator according to  claim 1 , w herein a cylindrical spacing sleeve of optional length is thread on the transfer element and abuts with a first end thereof against a stop on the protecting tube at the second part of the transfer element, and when the transfer element is mounted in a hole of the stationary casing a second end thereof rests against the exterior wall of the stationary casing a second end thereof rests against the exterior w all of the stationary casing, thus defining the position of the transfer element and the receiving head. 
     
     
       12. The centrifugal separator according to  claim 11 , wherein said nozzles are permanently open. 
     
     
       13. The centrifugal separator according to  claim 11 , wherein said nozzles are intermittently openable. 
     
     
       14. The centrifugal separator according to  claim 2 , wherein the sensor element is attached to the end of the second part of the transfer element. 
     
     
       15. The centrifugal separator according to  claim 2 , wherein the transfer element is manufactured of a material configured to permit said propagation of vibrations from the receiving head to sensor element. 
     
     
       16. The centrifugal separator according to  claim 3 , wherein the transfer element is manufactured of a material configured to permit said propagation of vibrations from the receiving head to sensor element. 
     
     
       17. The centrifugal separator according to  claim 1 , wherein the axis of the transfer element is spaced from the axis of rotation. 
     
     
       18. The centrifugal separator according to  claim 17 , wherein the axis of the transfer element is tangential to the rotor. 
     
     
       19. The centrifugal separator according to  claim 1 , w herein the transfer element has a first end and a second end, w herein the sensor element directly contacts the second end of the transfer element, and w herein a cylindrical holder surrounds the transfer element and sensor element. 
     
     
       20. The centrifugal separator according to  claim 1 , wherein the protecting tube extends into the stationary casing.